Girl on a mission
by Catreadsbooks
Summary: SPOILERS FOR CITY OF LOST SOULS! Isabelle Lightwood is a girl on a mission. Her target? Simon Lewis. SPOILERS FOR CITY OF LOST SOULS! Only read this if you have read CoLS!


**After finishing City of Lost Souls, I just needed some Sizzy. I came up with this and hope Simon/Isabelle will become canon in City of Heavenly Fire.**

**I don't own The Mortal Instruments or Star Wars.**

**~ Enjoy ~**

**Girl on a mission**

Isabelle Lightwood was on a mission. A mission that scared the hell out of her. You'd think that as a Shadowhunter, she would be used to the rush of adrenaline through her veins but this wasn't a normal mission. It didn't even concern the Shadowhunters and the upcoming evil. It was something much more personal and involved the thing that was dearest to Isabelle, her own heart. Why her heart you ask? Because Isabelle Lightwood was on her way to tell Simon Lewis that she liked him and wanted to be with him.

Izzy rushed down the Institute's corridor and turned around one last time to look at Clary who appeared be to talking to Brother Zachariah; Clary who had somehow become her best friend and who had told her to talk to Simon. If there was one person in the world who really knew Simon, it's Clary Fray and Isabelle had learned to trust and to listen to the short redhead.

Hearing her own pulse in her ears, Izzy stormed into her room and reached for her whip and her stele. She briefly considered changing into a different outfit but then dismissed the thought. Simon had seen her in gear, party outfits and also his clothes, he never seemed to mind her appearance.

She only ran a brush through her dark hair that tumbled over her shoulder like black silk. Taking a final deep breath, Isabelle left her room and headed for the elevator. Ahead in the corridor she saw and heard her brother closing his door with a deafening bang. She shook her head but didn't change direction; she was on a mission after all.

Once Isabelle was outside, a terrifying yet also elating thought struck her. _The next time I enter the Institute, Simon might be my boyfriend. _A shiver ran down her spine. Simon and Isabelle, Isabelle and Simon. It sounded nice. Better than nice actually, it sounded right. Just like she felt when he had held her in his arms and told her the entire plot of the Star Wars movies as a bedtime story. Magnus had mocked Simon afterwards but she had thought that it was sweet. She liked his nerdy side because it had been a part of his old life, a life she wanted to know more about. Isabelle wanted to know so much more about Simon.

Feeling a little breathless because every step brought her closer to exactly this opportunity, she turned to the busy New York streets and hailed a cab. The cab ride passed in a blur, she either wiped her hands on her jeans or readjusted her red sweater that constantly slipped down her shoulder. Isabelle was so focused on distracting herself that she didn't notice the cab stopping until the driver grunted out the price. She hastily paid him and then left the car to stand in front of the apartment building where Simon now lived with Jordan.

Isabelle's pulse increased even further and before she could chicken out, she pressed the buzzer for the doorbell. There was a low static, then "Yeah?" _Simon. _Her heart jumped and her mouth suddenly felt dry. She longed for a glass of water but knew that it was just nerves. _You can do it, Izzy. _"It's Isabelle." Hey, I'll buzz you up." Was it just her or did he sound cautious? Her heart jumped again but this time she willed it to calm down, was there something wrong with Simon?

Isabelle got her answer when Simon opened the apartment's door and a pretty girl who looked a lot like him sat on the couch. Izzy slowly entered the room and breathed an inner sigh of relief when Simon almost unconsciously rested his hand on the small of her back to take her to his sister. "Iz, that's my sister Rebecca. Becky, this is Isabelle." Becky got up and scrutinised Isabelle who took a step closer to Simon and immediately cursed herself for it. _By the Angel, she's just a mundane!_ But she knew that that wasn't true. If things turned out the way Isabelle wanted them to be, Becky would be her boyfriend's older sister and a direct link to Simon's old life.

Becky finally smiled and held out her hand. "Hello, it's nice to see that Si knows other girls besides Clary. It took him long enough." Izzy quickly shook the offered hand, managed a _hi_ and felt Simon relax at her side. "I know plenty of girls, Becky," he remarked. "Sheila the thong doesn't count. I'm just glad you finally got over Clary and found someone else." Isabelle blushed and Simon cleared his throat. "We're not dating, Becks." "Could have fooled me, you seem very familiar with each other." "We used to date," said Izzy bluntly. Simon sighed. "Let's not go there, Iz, Rebecca is my big sister and doesn't have to know everything." Becky watched her brother who gave her a weak smile and then turned to Isabelle. "I better be off, I'm sure you are here for a reason and I have some things to do. It was nice meeting you." Izzy smiled. "Thank you. Perhaps we'll see each other again?" Becky gives a sly grin and responded while watching her brother who looked a bit uncomfortable all of a sudden. "Oh, I'm sure we will. - I'll call you later, Si." With a wave to both of them she left the apartment.

Once they were alone, Izzy's heart was racing again and her legs felt like jelly. "Your sister seems nice," she mumbled. Grimacing, she cleared her throat and tried again. "You have the same eyes." Simon smiled and rested his hands on her hips, drawing Izzy closer to his body. "She's the best. I told her what I am and she didn't run away screaming. Becky will help me with our mum." "She knows?" His forehead wrinkled. "Yeah, I don't care that I wasn't allowed to tell her, she's my family and…" "No. Simon, that's not what I meant." Isabelle brushed her thumbs over his cheekbones. "It's good that Becky knows. I was just surprised." Simon's mouth quirked up and Isabelle suddenly remembered being in the apartment, telling Jordan about his roommate's smile. She ducked her head and her hands left Simon's face. They trailed down his chest until they rested on his sides. He stepped closer to her until their chest touched and his hand tilted up her face. He looked into her eyes which seemed to swallow him up. Isabelle felt colour creeping into her cheeks but she held his gaze. "You look beautiful." Her cheek flushed even more and her eyes sparkled. Simon lowered his face to hers but before he could kiss her, Isabelle drew away. "Wait! I … I need to know how you feel about me before I let you kiss me." She felt lightheaded and her heart beat so wildly now that she's sure that Simon could hear it as well.

"I think about you all the time. I like laughing with you, I like spending time with you and I miss you when you're not around. When you faced Raziel I was so scared it took my breath away. I cursed myself for not telling you how I felt but you are here now and alive so I can tell you. I want to be with you, Simon. It's terrifying me but I want to be with you … if you want to be with me, too." Simon didn't know whether to look stunned or happy but happiness won and he pressed his forehead to hers. "Isabelle … I'm not really good with words but yes, I want to be with you, too. I want to call you my girlfriend, for real this time." Izzy's eyes lit up and Simon was once again surprised to see that they weren't black after all. "It's ok to kiss you now, right?" She grinned and nodded. "That's what boyfriends do." Simon bent his head and then he was kissing her. His lips softly moved against hers and his hand buried themselves into her dark hair. Isabelle let herself fall against him and for the next few minutes nothing was important but them, there was no upcoming war against Sebastian and his Dark Shadowhunters and no worrying about Jace or her family. Simon was all she breathed, felt, heard and smelled.

Later they lay intertwined on the couch and Simon ran his hands through her hair. Isabelle sighed happily and looked up at him. "I might be in love with you." If his heart could still leap, it would have leaped after her confession, instead Simon simply answered. "I know." Isabelle scowled and pinched his side. "This is still too new to start quoting Star Wars!" Simon's hands came to a halt in her dark tresses. "I thought you liked Star Wars." "I did but I bet Leia wasn't happy either when Han told her that after she told him _I love you_." He smiled sheepishly at her. "I'm sorry then, let me make it up to you."

And he did.


End file.
